PCDD/F EMISSION FROM LEBLANC SODA FACTORIES IN GREAT BRITAIN, FRANCE AND GERMANY DURING THE 18th TO EARLY 20th CENTURY

Balzer Wolfgang1, Gaus Martin1, Gaus Caroline2, Urban Ulrich3, Weber Roland4 1CDM Consult GmbH, Neue Bergstraße 9-13, 64665 Alsbach-Hähnlein, Germany 2National Research Center for Environmental Toxicology, University of Queensland, Brisbane 4108, Australia 3HIM GmbH, Waldstraße 11, 64584 Biebesheim, Germany 4POPs Environmental Consulting, Ulmenstrasse 3, 73035 Göppingen, Germany

Introduction It has only recently been recognised that high concentrations of dioxins can be formed under the Leblanc Soda and associated processes1,2. The Leblanc process can be considered the birth of the in the late 3-7 th 1700s and was used extensively untill the early 20 century to produce sal soda/ (Na2CO3) from (NaCl) as basic reagent for the , glass and textile industry. The HCl generated caused heavy environmental damages and was partly recycled to produce /calcium hypochlorite (bleaching powder). In the late 1980s, high levels of arsenic and lead were detected in soil from Lampertheim, Germany (approximately 60 km south of Frankfurt/Main)1 during the construction of a child care facility and playground. Subsequent investigations in the 1990s also revealed highly elevated PCDD/F levels in soil from the same estate, which was used as a residential area. Based on these findings, the German State Hessen commissioned investigations into the history of the estate, and extensive soil and groundwater analyses. These investigations demonstrated that the contamination originated from a Leblanc factory which operated from 1828 to 1927 on the estate1. The total dioxin formation (particularly PCDFs) during this operation amounted to 1-10 kg TEQ1. The facility ceased production in 1927/28, after which it was demolished and partially levelled. From the 1950s onwards, the area was opened for residential housing development and approximately 600 people live within 125 blocks on this estate today. Since the discovery of high contamination levels in residential soil, extensive securing and remediation measures are ongoing and are expected to be finalized in 20101. With the Leblanc process representing an important production process during the , the findings from Lampertheim suggest that other similar contaminated sites exist elsewhere. Since the Leblanc sal soda production had not previously been identified as a potential PCDD/F emission source, the associated operational settings and processes resulting in PCDD/F formation and emissions were unknown. This presents information from historic investigations into the development and former operations of the Leblanc factory in Lampertheim and other similar operations in Germany, France and Great Britain. Further, the PCDD/F formation potential during the different operational steps of the Leblanc factory were evaluated. These two aspects provide an important basis for identifying contaminated sites and assessing the contemporary relevance of this historical dioxin source.

Materials and Methods Historical investigations were carried out by extensive searches of archives as well as the scientific literature. Based on these investigations, detailed analyses of surface and subsurface soil as well as production residues from the residential estate and nearby former landfill of the factory in Lampertheim were undertaken during 1994 to 1999. More than 600 soil cores of a total length of 3 km were taken on and near the estate and more than 3,500 soil analyses were carried out for a range of organic and inorganic1 contaminants. Selected samples (approx. 500) were also analysed for PCDD/PCDF according EN 1948 by commercial laboratories.

Results and Discussion Analyses of soil from the Lampertheim estate confirmed that the entire surface and subsurface soil, in some locations up to a depth of approximately 8 meters, was highly contaminated with PCDD/Fs, heavy metals and arsenic, the latter in bioavailable form1. Since a range of chemical processes are employed in a Leblanc factory, the individual steps and processes were evaluated with respect to their PCDD/F formation potential. Four distinct Leblanc operational steps could be identified that have a high potential to result in PCDD/F formation and were further evaluated:

Organohalogen Compounds, Volume 70 (2008) page 000809 1) The production of sodium sulphate and sal soda within ”sulphate ovens” and flame ovens3: A main part of all Leblanc processes is the production of sodium sulphate (Na2SO4) and HCl from sodium chloride (NaCl) and sulphuric acid (H2SO4). In the first step of this production process, NaCl reacts with H2SO4 in iron pans at 200 °C (“sulphate ovens”). This results in the release of approximately two thirds of the added chloride, mainly as HCl3. The sulphate ovens were impregnated with tar to protect from HCl3 corrosion, providing the most basic conditions known to result in PCDD/F formation (i.e. chlorine, coal tar and heat). In a second step, the remaining NaCl was converted to Na2SO4 in flame ovens operating at 600 °C. The surfaces of 3 the ovens were frequently cleaned from deposits. The Na2SO4 were converted with coal and 3 to NaCO3 in soda ovens at 900 °C . Residues from these processes were contaminated with up to 95 ng TEQ/kg.

2) The processes used for condensation and purification of hydrochloric acid3 In the Lampertheim factory the produced in the above step was condensed in coke towers for further processing. In these towers, mineral oil in counter flow, was used to remove arsenic. The pipes and condensation chambers leading from the sulphate and flame ovens to the coke towers were mainly constructed of clay soaked with coal tar. The temperature in the off-gases was 160 °C from the sulphate ovens and 360 °C from the flame ovens. The cooled gases were adsorbed in a concurrent water flow to produce HCl and for the further production of chlorine. Conditions favouring PCDD/F formation during the condensation and purification of HCl are confirmed by PCDD/F contamination in soil where the piping system and the coke towers were formerly located. PCDD/F concentrations in these soils were above the German soil guidelines for industrial sites (>10,000 ng TEQ/kg).

3) The production of chlorine A) oxide based processes Before the chloro alkali processes was invented I) Direct oxidation around 18902, chlorine was produced via MnO2 + 4 HCl → MnCl2 + Cl2 + 2H2O manganese oxide by direct or indirect oxidation II) Indirect oxidation of HCl (Figure 2). In 1868, Deacon invented the MnO2 + 2 NaCl + 2 H2SO4 → MnSO4 + NaSO4 + Cl2 +2H2O oxidation of HCl using CuCl catalysts as an (Walter Weldon improved 1870 the manganese process by 2 recycling of the MnCl via air oxidation in alkaline solution) alternative process. In Lampertheim, the direct 2 B) Deacon process manganese oxide method was used for chlorine 4HCl + O → 2Cl + 2H O (400 – 450 ºC; CuCl2 catalyst) production from HCl. Neither the Deacon 2 2 2 Figure 1: Chlorine production processes used before the process nor a chloro alkali was operated on the invention of the chloro alkali process site. For this manganese oxide method, the chlorine cells were built from sand stone. 0,4 Chloralkali Coal tar was used as filler material (approx. 2 cm) between the stones3. Additionally, the Soil near Sulphate Oven 0,3 stones were soaked with coal tar for Residue near Chlorine 3 protection of corrosion . It is obvious that Prod. (MnO-process) this process had a high potential for 0,2 PCDD/F and other Cl-PAH formation from coal tar and elemental chlorine. This process reached temperatures of up to 90 °C with a 0,1 residence time of 12 hours.3 These conditions are similar to those employed by the chloro alkali electrolysis using coal tar 0 D D D D F F F DD D D D DD DF DF DF DF containing graphite electrodes. In C CD C CD CD CDF C C C C CD

2,3,7,8-Congener Distribution Distribution (mass) 2,3,7,8-Congener T eC x xC xC p T e e x O - OCDD P P H ,8 -P -H H H -H ,8- - - - -Hx -Hp -Hp Lampertheim, the vicinity of the area where 7 8 8- 9- 8 7 ,8 ,9 ,8-HxCDF8 ,9 , , , , , , 7, ,3 ,7,8 ,8 ,7 ,7,8 ,7 ,8 7 , ,8 2 ,3,7 4 ,6,7 ,7 ,6 2,3 3 ,6 ,7 ,6, ,6 ,7 the chlorine/chlorinated chalk were formerly ,2 ,3, 3 ,3 ,4 ,2, ,3 1 ,2, ,2 ,3 1 2,3,4,7,8 ,2 ,2,3 ,3,4 ,3,4 ,3,4 1,2 1 1 ,2 1,2,3,4,7,8-HxCDF1 1 2 2 ,2 produced, high contaminated residues with 1 1, 1 TEQ levels above 200,000 ng TEQ/kg were Figure 2: 2,3,7.8-congener pattern of soil near former sulphate ovens found. The PCDD/F pattern of these and residues near former chlorine production (manganese method) residues are similar to those characteristic of compared to chloro alkali electrolysis. the chloro alkali process.

Organohalogen Compounds, Volume 70 (2008) page 000810 4) The production of calcium hypochlorite (bleaching powder) Calcium hypochlorite was produced from Ca(OH)2 and elemental chlorine in chlorine chambers. For this, , stone or lead/iron chambers were commonly used. The wood and stone chambers were completely covered with coal tar. After distributing the Ca(OH)2 on the floor of these chambers (75-100 mm), they were filled with chlorine for a reaction time of approximately 24 hours under an average operating temperature between 55-90 °C and peak temperatures of up to 120°C3. Based on this, this process can be considered having optimized conditions for PCDD/F formation when coal tar was used as insulation material.

Other processes operated in this Leblanc factory (sulphuric acid production, phosphate fertilizer production, nitric acid) were not considered as a relevant PCDD/F source based on evaluation of the associated reagents, catalysts and operating conditions.

Other Leblanc operations During our historical investigations, 14 further locations were identified in Germany where Leblanc factories have been operated in the past. These locations and other details are listed in Table 1. According to historical records of sal soda production from the Leblanc process, Germany contributed only 66,000 tonnes to the total 413,000 tonnes sal soda produced in 18654. The main producers of sal soda via the this process were located in England (234,000 tonnes) and France (108,000 tonnes).

The Leblanc process was invented in France by Nicolai Leblanc and started operation in 1791 in Saint-Denis (near Paris)4-7. Before 1800, two factories were established in Marseille and Lille (Treue), and around 1808, two factories became operational in Paris4. From 1812, Marseille was considered the center of Leblanc Soda production in France, with 30 facilities in and around the city. Finally, from the 30 facilities more then a dozen factories survived the competition around Marseille covering 75% of the French production6.

Soon after the introduction of the Leblanc process, the production volume of soda in Great Britain represented the most extensive in the world, exceeding that of all other countries combined. One of the first plants, owned by , commenced operation in 1823 and was located on the banks of the Mersey River in Liverpool. Another plant, owned by , commenced operation around the same time at St. Rollox, near Glasgow, where the factory had already earlier produced calcium hypochlorite (as bleaching powder). Another centre of Leblanc soda production was located at the River Tyne in Northeastern England, where the country’s first Leblanc small-scale works were built in 1816 and in South Lancashire (St. Helens, Runcorn Gap, Widnes Dock, Warrington, Bolton, Newton Health). Another larger Leblanc factory was located in Oldbury, five miles West of Birmingham. In total, approximately 30 to 40 Leblanc factories were operating in England during the mid 19th century4, 5, 14.

Only a few factories in other European countries were listed in literature Prag (Czech Republic)10, Oberalen/Hallein (Austria)10, Utrecht (Netherlands)10. A modified Leblanc process was operated in the United States on a small scale to prepare alkali directly from sodium sulphate7.

Overall, this survey revealed that at least 70 to 100 Leblanc factories were operated during the 19th century mainly in Great Britain, France and Germany. Since several of the basic processes employed during the Leblanc soda production have a relevant PCDD/F formation potential, any former Leblanc factory estate, even if not involved in chlorine production, should be considered as potentially contaminated with PCDD/Fs. The same conclusion should be drawn for other key contaminants produced during this process (e.g. lead, arsenic and other metals and metalloids). The amount of PCDD/Fs and potentially also the specific pattern emitted at each of these sites should be expected to vary depending on the specific operation history of the plants. In the absence of information on such detailed data, however, PCDD/F loads at Lampertheim may serve as an approximate estimate on the dioxin contamination associated with comparable production sites. The experience gained there can be valuable and applicable for the investigation of other former Leblanc sites.

Organohalogen Compounds, Volume 70 (2008) page 000811 The sites identified as part of the present study should therefore be investigated with respect to their contemporary land use, contamination levels, potential for off-site migration of contaminants and associated requirements for remediation. That this source remains of relevance today is apparent at the contaminated site in Lampertheim where PCDD/Fs (and other persistent organic and inorganic pollutants) posed a risk to the environment and humans, even after more than a century since their emission.

Table 1: Leblanc soda factories in Germany (confirmed adjacent production of chlorine/bleaching powder). 1) Schonebeck an der Elbe4 2) Ludwigshalle zu Wimpfen am Neckar4 3) Kaferthal bei Mannheim; Chemischen Fabrik Wohlgelegen4 4) Lampertheim/Worms, Fabrik Neuschloss (with bleaching powder) 4 5) Duisburg; Matthes & Weber (with chlorine; bleaching powder) 4 6) Karlsruhe10 7) Heilbronn4 8) Ringenkuhl bei Kassel; Pfeiffer, Schwarzenberg & Co4 9) Barmen; Friedrich Siebel & Co4 10) Ludwigshafen; BASF4 11) Pommerensdorf bei Stettin (with bleaching powder) 4 12) München and Augsburg; Bosch & Co11 13) Schönebeck10 14) Buckau/Magdeburg; Chemische Fabrik Buckau12 15) Stollberg; Waldmeister/Rhenania13

References 1a. Balzer W. Gaus H.-M, Gaus, C. Weber, R.; Schmitt-Biegel, B., Urban U. Organohalogen Compd. 2007, 69:857. 1b. Institut Dr. Neumayr GmbH (now: CDM Consult GmbH), Nutzungshistorie der ehemaligen chemischen Fabrik in Lampertheim-Neuschloß, 1994. 2. Weber R, Tysklind M, Gaus C Dioxin – Contemporary and Future Challenges of Historical Legacies (Editorial, dedicated to Otto Hutzinger). Env Sci Pollut Res 2008, 15 (2):96–100. 3. Lunge G. Handbuch der Soda-Industrie und ihrer Nebenzweige. Vieweg Verlag, Braunschweig (1879). 4. Treue W. Die Entwicklung der chemischen Industrie von 1770 bis 1870. Chemie Ing. Techn. 1967, 39 (17), 1002-1008. 5. Encyclopaedia Britannica 1911; 11th Edition. http://www.1911encyclopedia.org/Alkali_Manufacture 6. John Graham Smith. The origins and early development of the heavy chemical industry in France. Oxford Clarendon Press, 1979. 7. Kiefer D.M. It was all about alkali. Today’s Chemist at Work. 2002, 11: 45–46. 8. Rappe C, Kjeller L-O, Kulp S-E, de Wit C, Hasselsten I, Palm O. Chemosphee 1991; 23:1629. 9. Bundesbodenschutz- und Altlastenverordnung, BGBl I, 1999; Nr. 36:1554. 10. Pierer's Universal-Lexikon. Altenburg 1857-1865, Band 16: 237-240. 11. Ch. Hölz; Der Civil-Ingenieur Jakob Kreuter, Tradition und Moderne 1813 – 1889, Berliner Kunstverlag 2003. 12. Hackenholz D. Die elektrochemischen Werke in Bitterfeld 1914-1945.. LIT Verlag Berlin Hamburg Münster 2004. 13. Friedrich H. Alphabet der Heimatkunde zu den Themen: Geologie Bergbau Metallindustrie, Version 3.3; Mai 2007. 14. Jahresbericht über die Fortschritte der Chemischen Technologie für 1882.

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